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AstroAlert

Know exactly when satellites pass above you.

AstroAlert is your personal sky-watch assistant. It tells you exactly which satellites, planets, comets, and deep-sky objects will pass right above your location in the next 24 hours — including spectacular zenith events above 70°. Powered by NASA/JPL data, it combines real-time calculations with educational content, a full astronomy glossary, and detailed object sheets. The sky above you, revealed with precision.

Top comment

🚀 Hello Product Hunt! I’m thrilled to introduce AstroAlert — a project I built because I always missed spectacular satellite passes without knowing they were happening above me. AstroAlert calculates all major sky events for your exact location: satellites, planets, comets and even deep-sky objects. I’d love your feedback: what celestial object would YOU like to track next? Happy to answer every question! ✨